Helping Beethoven hear
How gene therapy could become the first therapeutic for genetic hearing loss
Little progress has been made in developing therapies for hearing loss that go beyond the temporary and partial solutions provided by hearing aids and cochlear implants, and most company activity is focused on acquired forms of the disease. Now, a group at Boston Children's Hospital has looked at genetic causes of deafness and designed a gene therapy to restore function in TMC1, one of the disease's most commonly mutated targets.
Attempting gene therapy is still relatively uncommon in hearing loss. Novartis AG and GenVec Inc. have the CGF166 gene therapy in Phase I/II testing for acquired hearing loss, but the majority of companies in the space have programs based on small molecules. (See Table: Commercial programs in hearing loss)
Now, in a study published in Science Translational Medicine, the Boston researchers have shown that TMC1 gene therapy reversed hearing loss in the Beethoven strain of mice that modeled an adolescent-onset form of the disease, and restored function in a second model that mimicked neonatal deafness.
Jeffrey Holt, principal investigator on the study, told BioCentury that the ear is a good organ for gene therapy because, like the eye, it is a relatively self-contained, fluid-filled space. "What you inject into the inner ear tends to stay there and not go systemic," he said.